A philosopher, theologian, and writer, born at Salerno, Italy, 14 August, 1810; died at Rome, 18 October, 1892. He studied at the College of the Jesuits at Naples in 1825, and a year later applied for admission into the Society of Jesus, His remarkable innocence, brilliant talents, and strength of character made him a most acceptable candidate, and he entered the novitiate on 9 October, 1826. The long course of studies was completed by him with unusual success, and resulted in his teaching philosophy for the space of eleven years, from 1837 until the Revolution of 1848 drove him to Malta. On returning to Italy he was appointed to teach theology, but gave up his professorship to found and assume charge in 1850 of the "Civiltà Cattolica", a periodical founded by the Jesuits to defend the cause of the Church and the papacy, and to spread the knowledge of the doctrine of St. Thomas Aquinas. Indeed it is Liberatore's chief glory to have brought about the revival of the Scholastic philosophy of St. Thomas. This movement he inaugurated by publishing his course of philosophy in 1840, at a time when the prevailing methods of teaching that science, even among certain Catholics, were, to say the least, little calculated to provide solid foundation for Catholic doctrine. This movement he supported to his dying day by his teaching in the class-room, by textbooks on philosophy, by able articles in the "Civiltà Cattolica" and other periodicals, by larger and more extensive works, and also by his work as member of the Accademia Romana by appointment of Leo XIII.

For more than half a century he was the tireless champion of truth in the fields of philosophy and theology, and of the rights of the Church. His pen was constantly at work, analysing the vexed problems of Christian life both theoretical and practical, marking out the relations between Church and State, and the moral and social aspects of life. His watchfulness over the foundations of the faith is attested by his successful struggles with Rationalism, Ontologism, and Rosminianism. His literary activity may be estimated from the fact that Sommervogel records more than forty of his published works, and gives the titles of more than nine hundred of his articles (including reviews) which appeared in the "Civiltà" alone. The most prominent characteristics of his writings are keenness of judgement, strength of argument, breadth of learning, logical sequence of thought, close observation of facts, knowledge of men and of the world, and simplicity and elegance of style. He has been regarded by many as the greatest philosopher of his day. It is a tribute to his holiness of life and deep religious spirit that his brethren of the Society of Jesus were Less impressed by his varied talents and immense learning than by the many virtues displayed during his long and fruitful life as scholar, professor, writer, academician, director of souls, and rector. His name will long be in blessed memory among all those who love the Church. The following are the best known, perhaps, of his works: "Institutiones Philosophicæ"; "Instructiones Ethicæ"; various compendiums of logic, metaphysics, ethics, and natural law; "Della Conoscenza intellettuale"; "Del Composto umano"; "Dell' Anima umana"; "Degli Universali"; "Chiesa e Stato"; "Dialoghi filosofici"; "Il Matrimomo"; "Roma e il mondo"; "Il Matrimonio e lo Stato"; "Le Commedie filosofiche"; and "Spicilegio".